//文本框默认提示文字
$(document).ready(function(){
    $(".spanJoin").click(function(){
        $(".imgJoin").slideToggle("slow");
        $('html,body').animate({
                scrollTop: 150},700)
    });
    $(".spanContact").click(function(){
        $(".imgContact").slideToggle("slow");
        $('html,body').animate({
                scrollTop: 150 },700)
    });
    var username = document.getElementById("username");
    if(username != null && username.value!=""){
        $(".placeholder1").hide();
        $(".username").css("background-color","floralwhite")
    }
    var identify = document.getElementById("identify");
    if(identify != null)
        identify.value="";
});
